As a result of inadequate funding for treatment, waiting lists for opioid treatment programs (OTPs) persist, and new and more effective approaches for expanding treatment access and improving outcomes are needed. This competing renewal application seeks to build on our parent R01 study, which was the first randomized clinical trial of interim methadone treatment conducted under existing federal regulations. Research resulting from the parent study has demonstrated that interim treatment (methadone with only crisis counseling) in comparison to wait list control, was associated with greater entry into comprehensive OTPs, lower self-reported heroin and cocaine use, lower rates of opioid-positive drug tests, and lower rates of self-reported crime at both 4- and 10- month follow-up (Schwartz et al., 2006 and in press). A parallel two-group randomized study is proposed, in which adult heroin-dependent subjects (N = 300) who meet federal criteria for OTP entry and for whom no treatment slot is available, will be randomly assigned at three community-based OTPs to either interim methadone treatment or prompt admission to comprehensive methadone treatment. Following federal guidelines, all interim treatment subjects who have not gained entry into a comprehensive OTP by 120 days (4 months) from study entry will be admitted to comprehensive treatment. Outcome will be assessed by measuring enrollment in comprehensive treatment at 4 and 12 months from baseline, as well as participants'illicit drug use, HIV-risk behavior, and criminal activity at baseline and at 2, 4, and 12 months post-baseline. We hypothesize that prompt entry to comprehensive treatment will have outcomes superior to interim treatment. Furthermore, participants with lower motivation for treatment are hypothesized to respond more positively to interim maintenance than to comprehensive treatment, because of potentially aversive features of comprehensive treatment, particularly confrontation in counseling. Finally, a cost benefit analysis will be conducted to determine the related costs and benefits of interim treatment v. comprehensive treatment. The results of this study will provide important information to researchers, clinicians, and public health policymakers regarding the relative effectiveness and benefits of these two approaches to OTP treatment.